The invention relates to filling vehicles with fuel, and more precisely to the end-pieces with which vehicles are equipped to cooperate with the supply spout at the end of a fuel supply nozzle. It is known that the outside diameter of the supply spout of such a nozzle has in practice a value that is a function of the fuel distributed. Thus the supply spout of a nozzle belonging to a pump delivering diesel has a greater diameter than the supply spout of a nozzle belonging to a pump delivering unleaded petrol.

There are known already, notably from French patent 2 868 738, various measures adopted so that the end-piece of the filler pipe of an unleaded petrol vehicle cannot accept the supply spout of a diesel pump supply nozzle; such a supply spout, because its diameter is greater than that of an unleaded petrol supply spout, cannot enter an aperture calibrated to this end.

There are also known, notably from European patents 1 262 355, 1 262 356, 1 284 212 and 1 319 545 and International application WO 2005/077698 various measures for solving the opposite problem, i.e. preventing an unleaded petrol pump nozzle supply spout being introduced into a diesel vehicle filler end-piece.

In the application WO 2005/077698, the end-piece includes an actuation ring provided with a slot and an inlet portion that narrows toward the tank, the narrowest cross section of the inlet portion being smaller than the diameter of a diesel supply spout and larger than that of an unleaded petrol supply spout. The end-piece also includes a shutter which in the closed position forms an abutment for the supply nozzle of an unleaded petrol pump that has been inserted.

At its end facing toward the tank and on at least one side of the slot, the actuation ring has an actuation part that is adapted to interengage with the shutter, and move the latter from a closed position to a disengaged position when the insertion of a diesel pump supply nozzle spreads the actuation ring.

However, it has been found that in extreme manipulation cases, it was possible to move the shutter into a disengaged position by pressing with the end of the supply spout of an unleaded petrol nozzle on the shutter and applying a lateral movement.

The invention is directed to a filler end-piece of this kind provided with a polarizer device of improved performance.

To this end it proposes a vehicle fuel filler pipe end-piece adapted to enable entry into said pipe only of a diesel supply spout, said end-piece including a protection assembly including:

- a plate having a passage aperture;

- an actuation ring adapted to adopt a service position in the absence of an external load, said actuation ring being deformable against elastic return forces urging it toward said service position, said ring including a slot and an inlet portion that narrows toward said pipe, the narrowest cross section of said inlet portion being less than the outside diameter of a diesel supply spout and greater than the outside diameter of an unleaded petrol supply spout, said actuation ring including an actuation portion disposed on one side of said slot;

- a shutter mobile in rotation relative to said plate, adapted to adopt a service position in which it at least partially masks said passage aperture and forms an abutment for a said unleaded petrol supply spout and a disengaged position in which it does not mask said passage aperture, said actuation portion being adapted to cooperate with said shutter so that said shutter is moved toward said disengaged position by said actuation portion when said actuation ring is spread radially by inserting a diesel supply spout in said inlet portion, characterized in that:

- said plate includes a recess having a bottom surface and a lateral border, said recess facing said shutter when it is in the service position;

- said shutter is also adapted to adopt, when acted on by a force exerted by an unleaded petrol supply spout when it is in said service position, a blocking position in which it is engaged in said recess and prevented from rotating by said lateral border so that it cannot be moved toward said disengaged position.

If the user attempts to introduce into the end- piece of the invention an inappropriate supply spout, i.e. an unleaded petrol supply spout, that supply spout penetrates it until its end comes to bear on the shutter, then causing it to swing and take up the rotation blocking position.

Thus even if this user attempts to force opening by exerting a lateral movement with the supply spout to pivot the shutter to the disengaged position, the latter abuts against the lateral border of the recess and remains in the blocking position.

The end-piece of the invention thus offers high security of use, by making it impossible or in any event particularly difficult for the user of an inappropriate supply spout to force the passage aperture to the tank.

According to preferred features, taken alone or in combination: - said shutter is disposed between said ring and said plate so as to have, in the service position, a first portion bearing on said plate and a second portion facing and overhanging said recess, said facing portion being adapted to swing in said recess in response to said force exerted by an unleaded petrol supply spout; - said shutter includes at one end a finger projecting transversely from said bearing portion, said finger being engaged in a notch in said plate so that said shutter is able to pivot about said finger; - said plate includes a second recess having a bottom surface and a lateral border, said second recess being angularly spaced from said first recess about said finger, said shutter also being adapted to adopt, in response to a force exerted by an unleaded petrol supply spout when it is in said service position, a second blocking position in which it is engaged in said second recess and prevented from rotating by said lateral border of said second recess, so that it cannot be moved toward said disengaged position; - said actuation portion of said ring includes an outwardly extending arm and a second finger disposed at the distal end of and extending on either side of said arm, said shutter further including a main wall and a rim projecting transversely to said main wall, said second finger being adapted to cooperate with said rim to move said shutter toward said disengaged position when said ring is spread radially on inserting a diesel supply spout in said inlet portion;

- said second finger is adapted to cooperate with said main wall and with said rim to move said shutter into its service position when said ring is elastically returned to its service position on withdrawing said diesel supply spout;

- said main wall of said shutter is adapted to raise said second finger to deform said ring in torsion when said shutter is moved from said service position to said blocking position by said unleaded petrol supply spout;

- said second finger is adapted to cooperate with said main wall to return said shutter to its service position when said ring is elastically returned to its service position on withdrawing said unleaded petrol supply spout;

- said inlet portion is formed by rigid radial ribs distributed at regular intervals over at least a portion of the circumference of said ring;

- said protection assembly includes a cup having a bottom wall including an aperture, the periphery of said ring bearing on said bottom wall and the distal ends of said ribs projecting from said aperture;

- said ring is adapted to pivot in said cup about a third finger projecting transversely from said bottom wall;

- said ring includes at its periphery an outwardly extending protrusion including a flat wall parallel to said bottom wall, said flat wall being adapted to retain said ring in said cup;

- said protection assembly includes a guide wall for a supply spout toward said inlet portion; and - said guide wall has a tapered shape that narrows in the direction of said inlet portion.

The explanation of the invention will now continue with the description of one embodiment, given hereinafter by way of nonlimiting illustration with reference to the appended drawings, in which:

- figure 1 is an exploded perspective view of the end-piece including a protection assembly and a blocking assembly;

- figure 2 is an exploded perspective view of the protection assembly of the end-piece from figure 1;

- figure 3 is a perspective view of the cup- actuation ring-spring subassembly of the protection assembly from figure 2;

- figure 4 is a perspective view of the plate- closure shutter subassembly of the protection assembly from figure 2, the shutter being in its service position;

- figure 5 is a perspective view from a different angle of the plate-closure shutter subassembly, the shutter still being in its service position; - figure 6 is a view in section of the plate- closure shutter subassembly in the figure 4 configuration on the plane marked VI-VI in that same figure;

- figure 7 is a view in section of the actuation ring of the protection assembly from figure 2, into which a diesel nozzle supply spout has been inserted;

- figure 8 is a perspective view showing the introduction into the protection assembly from figure 2 of the diesel nozzle supply spout from figure 7, some elements having been rendered transparent for better understanding of the mechanism;

- figure 9 is a view similar to that of figure 7, except that an unleaded petrol nozzle supply spout has replaced the diesel nozzle supply spout;

- figure 10 is a view similar to that from figure 8 except that the unleaded petrol nozzle supply spout from figure 9 has replaced the diesel nozzle supply spout;

- figure 11 is a perspective view from a different angle of the plate-closure shutter subassembly from figure 4, the shutter being in the blocking position; and - figure 12 is a view in section of the plate- closure shutter subassembly in its figure 11 position, on the plane marked XII-XII in that same figure.

The end-piece 1 shown in figure 1 includes an blocking assembly 2 and a protection assembly 3. The assembly 2 and the assembly 3 are provided to block the pipe securely in a service configuration and to authorize, starting from the service configuration, by a simple pushing movement, the passage of the supply spout 4 of an appropriate fuel, here diesel, supply nozzle through the assembly 3 and then the assembly 2, to reach the filling position, where the distal end of the supply spout 4 is in communication with the space inside the pipe (figures 7 and 8) .

The blocking assembly 2 includes a dome 80 having a globally cylindrical lateral wall 81 and a transverse end wall 82 of globally circular contour, having an eccentric passage aperture 83 for the supply spout 4.

The assembly 2 also includes, to the rear of the wall 82, a valve 85, mounted to swing on the dome 80 thanks to a device including a base 86, a rod 87 and a flap 88.

The valve 85 is furthermore continuously solicited by a return spring 89 to a position in which it blocks the aperture 83, and seals it thanks to a peripheral seal 90, the valve 85 being able to swing toward the rear to enable engagement of the supply spout in the aperture 83.

The protection assembly 3 is described in detail next .

As shown in figure 2, this assembly 3 includes a cover 10, a circular abutment 20, an actuation ring 30, a spring 40, a cup 50, a shutter 60 and a bottom plate 70.

Except for the spring 40, these various components are molded from plastic material.

The cover 10 includes a front wall 11 and a cylindrical lateral wall 12. The front wall 11 includes an introduction aperture 13 for the supply spout 4, this aperture 13 being formed in an eccentric position.

At its free end, the lateral wall 12 includes a rectangular notch 14 and clip tongues 15 for fixing it to the blocking assembly 2.

The lateral wall 12 also includes, on the inside, an indexing rib 16 which extends in a direction parallel to the axis of the cover 10 and over its full height

(i.e. from the front wall 11 to its free end). The circular abutment 20 includes a plane wall 21 of circular contour the diameter of which corresponds to the inside diameter of the cover 10, for mounting it in the latter, and in which there is formed at an eccentric position, an introduction aperture 22 for the supply spout 4.

In front of this plane wall 21, the circular abutment 20 includes a tapered wall 23 offset from the axis of the plane wall 21 and which narrows to the circular contour of the introduction aperture 22. The circular abutment 20 also includes on its external lateral side and over its full height an indexing notch 24 the contour of which is complementary to the section of the indexing rib 16.

The actuation ring 30, which has a globally circular shape, is provided with a slot 31 extending transversely over its full height (figure 3) .

It includes on the inside a plurality of rigid radial ribs 32 that are distributed at regular intervals over approximately two thirds of its circumference. The ribs 32 form an inlet portion 33 for the supply spout 4 that narrows toward the rear (i.e. toward the pipe and the tank) so that the narrower section of the inlet portion 33 is smaller than the outside diameter of the supply spout 4. In the vicinity of a first side of the slot 31, the actuation ring 30 includes an annulus 34 that projects radially outward.

In the vicinity of the second side of the slot 31, the actuation ring 30 includes an arm 35 that extends outward and in the direction of the annulus 34. At the distal end of the arm 35, a finger 36 extends on either side of the arm 35 along an axis parallel to the axis of the actuation ring 30 (figure 2) .

The actuation ring 30 also includes at its periphery a protrusion 37 that extends inward in the vicinity of the proximal end of the arm 35.

This protrusion 37 includes a plane main wall 37A that lies in a plane parallel to that of the ring and a transverse rim 37B. The spring 40 is of elastic metal wire (spring wire) . It includes a helically wound central portion 41 from which two hooks 42 and 43 project at opposite ends (figure 2) .

The cup 50 includes a cylindrical lateral wall 51 and a plane bottom wall 52 in which is formed, in an eccentric position, a passage aperture 53 for the supply spout 4 toward the blocking assembly 2 and the pipe.

The lateral wall 51 has a cross section whose external contour has a diameter identical to that of the circular abutment 20 and includes over its full height an indexing notch 54 (figure 3) the contour of which is complementary to the section of the indexing rib 16.

A finger 55 projects transversely and toward the front of the bottom wall 52 (figure 3) to enable, as described hereinafter, pivotal mounting of the actuation ring 30 about an axis corresponding to that of the central hole of the annulus 34.

In the vicinity of the finger 55 and the aperture

53, the lateral wall 51 and the bottom wall 52 each have a respective cut-out 56 and 57 in order to enable the finger 36 of the actuation ring 30 to cooperate mechanically with the shutter 60.

The lateral wall 51 also has another cut-out 58 that is situated in the area where the aperture 53 is closest to the border of the bottom wall 52, in order to enable placement of the actuation ring 30 in the cup 50

( figure 3) .

The shutter 60 (figure 4) includes a flat main wall

61 that extends longitudinally between an inverted V- shaped portion 62 the tip of which constitutes a first end of the shutter and a lug 63.

The shutter 60 also includes a rim 64 that extends along the two branches of the V-shaped portion 62 and projects transversely to the main wall 61 toward the front.

At the tip of the V-shaped portion 62 of the shutter 60, a finger 65 (figure 5) projects transversely to the main wall 61 toward the rear.

Between the V-shaped portion 62 and the lug 63, the main wall 61 has a rectilinear first lateral edge 66 and a globally circular-arc-shaped second lateral edge 67.

The bottom plate 70 has a circular contour the diameter of which is equal to those of the circular abutment 20 and the cup 50. A passage aperture 71 for the supply spout 4 toward the blocking assembly 2 and the pipe is formed therein in an eccentric position.

At the periphery, the plate 70 includes an indexing notch 72 the contour of which is complementary to the section of the indexing rib 16. In the vicinity of the indexing notch 72, the plate includes another U-shaped notch 73 adapted to receive the finger 65 in order to enable, as described hereinafter, mounting of the shutter 60 to pivot about an axis corresponding to that of the central hole of the notch 73.

Its front face 74 is delimited by a plane peripheral surface 75 forming a bearing surface for the shutter 60 and by two recesses 76 and 77 around the aperture 71. The recess 76 (respectively 77) is delimited by a bottom surface 76A (respectively 77A) parallel to the bearing surface 75, by a shoulder 76B (respectively 77B) transverse to that same surface 75 and by the aperture 71. The two recesses 76 and 77 are angularly spaced around the axis of the central hole of the notch 73. Assembly of the protection assembly 3 commences with pre-assembly of the subassembly consisting of the actuation ring 30, the spring 40 and the cup 50 (figure 4) . First the actuation ring 30 is placed in front of the aperture 53 so that the opening of the annulus 34 and the finger 55 are also facing.

The ring 30 and the cup 50 are then moved toward each other, so that the finger 55 is inserted into the annulus 34 and the distal ends of the ribs 32 project from the aperture 53, until the plane wall 37A of the protrusion 37 comes to rest on the bottom wall 52.

Finally, the hook 42 of the spring 40 is fixed to the front end of the finger 36 of the actuation ring 30 while the hook 43 is fixed to the front end of the finger 55 of the cup 50 (figure 5) .

Because the actuation ring 30 is mounted on the cup

50 to pivot about the finger 55, the user exerting a lateral force on the ribs 32 with the end of a supply spout of an unleaded petrol nozzle cannot under any circumstances command spreading of the ring 30.

In the eventuality of any such lateral force, the ring 30 pivots about the finger 55 until some ribs 32 abut against the contour of the aperture 53. Moreover, the flat wall 37A of the protrusion 37 holds the ring 30 in the cup 50, preventing the latter from swinging in the aperture 53 and escaping.

Assembly of the protection assembly 3 continues with pre-assembly of the subassembly consisting of the shutter 60 and the plate 70 (figures 4 to 6) . To this end, the rear face of the main wall 61 of the shutter 60 is disposed facing the first recess 76 of the plate 70 after which the finger 65 is engaged in the notch 73 until a portion 6OA (figure 6) of the shutter 60 located in the vicinity of the finger 65 comes to bear against the bearing surface 75 of the upper face of the plate 70, a second portion 6OB continuing to face and to overhang the recess 76. The shutter 60 is then in a service position, partially masking the aperture 71 as shown in figure 4.

As described hereinafter, the shutter 60 is adapted, once assembled to the plate 70, to be moved parallel to the surface 75 by pivoting about the axis of the notch 73. Moreover, the width of the notch 73 being slightly greater than the diameter of the finger 65 provides some clearance between these two components so that the shutter 60 can swing about the axis 68 (figure 11) in one of these recesses 76 or 77 if pressure is exerted on the shutter 60 at the aperture 71.

Assembly of the protection assembly 3 continues with introduction of the circular abutment 20 into the cover 10 by sliding the indexing notch 24 along the indexing rib 16. The same procedure is then followed with the actuation ring 30-spring 40-cup 50 subassembly, the indexing notch 54 sliding along the indexing rib 16.

Finally, the shutter 60-plate 70 subassembly is engaged so that the V-shaped portion 62 of the shutter 60 is vertically aligned with the finger 36 of the actuation ring 30 (as shown in figure 2) .

The indexing notch 72 is then slid along the indexing rib 16 until the plate 70 abuts against the cup 50 and the rear end of the finger 36 of the actuation ring 30 also abuts against the V-shaped portion 62 of the main wall 61 of the shutter 60.

The normal operation of the end-piece 1 is described next, i.e. its operation when a supply spout 4 of a diesel supply nozzle is inserted into it (figures 7 and 8) . Such a supply spout has a conventional outside diameter, i.e. of the order of 24 mm. The apertures 13, 22, 53, 71 and 83, which must allow the supply spout 4 passage, have a larger diameter, of course. The narrowest cross section of the inlet portion 33 of the actuation ring 30 is smaller than the outside diameter of the supply spout 4, so that when its end reaches this inlet portion 33 (having been introduced through the introduction aperture 13 and guided by the circular abutment 20 toward the aperture 22), its edge comes to bear on the ribs 32.

If the movement of pushing the supply spout 4 into the inlet portion 33 continues, the latter portion spreads the actuation ring 30 (figure 7), so that its finger 36 moves away from the finger 55 of the cup 50, causing the shutter 60 to pivot.

The pivoting of the shutter 60 continues until the passage aperture 71 is no longer masked by the shutter 60. In this disengaged position, shown in figure 8, the circular-arc-shaped second lateral edge 67 of the main wall 61 of the shutter 60 coincides with the contour of the plate 70.

The end of the supply spout 4 then passes through the apertures 53 and 71, after which its edge encounters the valve 85, which then swings back to allow the supply spout 4 to be introduced through the aperture 83, so that it reaches the interior space of the filler pipe.

After withdrawal of the supply spout 4, the spring 40 returns the finger 36 that cooperates with the rim 64 to return the shutter 60 to the service position shown in figure 4.

Exceptional operation of the end piece 1 is described next, i.e. its operation if a supply spout 4' of an unleaded petrol supply nozzle is inserted therein by mistake (figures 9 and 10) . Such a supply spout has an outside diameter of the order of 21 mm, which is smaller than that of the supply spout 4 and that of the narrowest cross section of the inlet portion 33 of the actuation ring 30. When the supply spout 4 ' is introduced into the protection assembly 3, its end passes through the apertures 53 and 71 without spreading the actuation ring 30 (figure 9) and therefore causing pivoting of the shutter 60. The end of this supply spout comes to bear a against the overhanging portion 6OB of the shutter 60 causing it to swing about the axis 68 in the first recess 76 of the plate 70, so that the shutter 60 finds itself in a first blocking position (figures 11 and 12) . Note that during swinging of the shutter 60, a portion of the main wall 61 is raised toward the front (notably the V- shaped portion 62), entraining with it the finger 36, the effect of which is to deform slightly in torsion the elastic ring 30 (figure 10) .

If the operator attempts to force introduction by pressing with the end of the supply spout 4' on the shutter 60 and exerting a lateral movement with the same supply spout 4 ' , the lug 63 of the shutter 60 comes to abut against the shoulder 76B of the first recess 76, preventing pivoting of the shutter 60. Should the operator succeed in bypassing this first security feature and cause the shutter 60 to pivot, the latter would then swing in the second recess 77 of the plate 70. It would thus find itself in a second blocking position, the lug 63 abutting against the shoulder 77B of the second recess 77 preventing pivoting of the shutter 60 to its disengaged position.

After withdrawal of the supply spout 4 ¹ , the elastic ring 30 tends to return to its rest position, which causes the finger 36 to be moved toward the rear. The latter finger then bears on the main wall 61 in the region of the V-shaped portion 62, the effect of which is to return the shutter 60 to its service position shown in figure 4.

In a variant that is not shown, the elastic ring has a somewhat different conformation, and in particular includes rigid radial ribs over the whole of its circumference. In other variants that are not shown, the shutter and the recesses of the spacer have different contours. In a further variant, the rear face of the main wall of the shutter includes an upstanding bead in the swinging area of the shutter, so that only this flute rests on the bearing surface of the shutter, thereby limiting friction when it pivots.